The total structure factor $S\left(Q\right)$ and the radial distribution function $G\left(r\right)$ of liquid ${\mathrm{Y}}_3{\mathrm{Al}}_5{\mathrm{O}}_{12}$ (YAG) were measured at 1770–2230 K by x-ray scattering from samples under containerless conditions in Ar and ${\mathrm{O}}_2$. Nominal coordination numbers are 4 for ${\mathrm{Al}}^{3+}$ and 6 for ${\mathrm{Y}}^{3+}$ ions. The $G\left(r\right)$ has peaks at $r\approx 1.8Å$ for Al-O, $r\approx 2.25Å$ for Y-O, and $r\approx 3.3–3.6Å$ assigned to metal ions in adjacent ${\mathrm{AlO}}_4^{5-}$ and ${\mathrm{YO}}_6^{9-}$ polyhedral ions. Relative to the pure oxides, $G\left(r\right)$ for molten YAG has smaller half-widths for the Al-O and Y-O peaks, and an increased sensitivity to temperature and the ambient gas composition.

• Received 27 September 1999

DOI:https://doi.org/10.1103/PhysRevLett.84.3622